Marcinkiewicz Designer/Signature mouthpieces are made to each specific player's specifications. Measurements such as inner diameter, venturi, etc., are not arranged systematically, however this line is also numbered progressively by cup depth from deep to shallow. Each endorsee chose a Marcinkiewicz Designer/Signature Mouthpiece because of their belief in the product. Each of these mouthpieces were designed for a specific player at a specific point in time. Many still play these mouthpiece exclusively.